Spark GridItemRenderer

[Deepak MS]

Hello,
I was generating columns for a datagrid dynamically, but wanted to align
number columns on right and hence I used following code to assign renderer
to the gridcolumn:

var gc:GrdiColumn = new GridColum('Growth');
var ir:ClassFactory = new ClassFactory(SpreadItemRenderer);
ir.properties = {textAlign:'right'};
gc.itemRenderer = ir;

SpreadItemRenderer.as :
public class SpreadItemRenderer extends GridItemRenderer
    {


        public var textAlign:String;
        public function SpreadFormatRenderer()
        {
            super();
        }

override protected function createChildren() : void
        {
            super.createChildren();
          if(labelDisplay)
           {
                labelDisplay.setStyle("textAlign", textAlign);
           }

        }
}


But, when I do that, column do not display any data in the datagrid. When I
debugged, I see that labelDisplay is always null. Isn't labelDisplay used
to display data under GridItemRenderer?

What am I missing here?

I am using Flex 4.12.0 | AIR 4.0 | FP 12.0 for a mobile app (iPad).